3,503 research outputs found

    Intertemporal and Spatial Location of Disposal Facilities

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    The optimal capacity and location of a sequence of landfills are studied, and the interactions between both decisions are pointed out. Deciding the capacity of a landfill has some spatial implications, because it effects the feasible region for the rest of the landfills, and some temporal implications because the capacity determines the lifetime of the landfill and hence the instant of time where the next landfills will need to be constructed. Some general mathematical properties of the solution are provided and interpreted from an economic point of view. The resulting problem turns out to be nonconvex and, therefore, it can not be solved by conventional optimization techniques. Some global optimization methods are used to solve the problem in a particular case to illustrate the behavior of the solution depending on the parameter values.Landfilling, Optimal Capacity, Optimal Location, Global Optimization.

    Intertemporal and Spacial Location of Disposal Facilities

    Get PDF
    Optimal capacity and location of a sequence of landfills are studied, and the interactions between both decisions are pointed out. The decision capacity has some spatial implications, because it affects the feasible region for the rest of landfills, and some temporal implications, because the capacity determines the lifetime of the landfill and hence the instant of time where next landfills will need to be constructed. Some general mathematical properties of the solution are provided and interpreted from an economic point of view. The resulting problem turns out to be no convex and therefore it can not be solved by conventional optimization techniques. Some global optimization methods are used to solve the problem in a particular case, in order to illustrate the behavior of the solution depending on parameter value

    PredicForex. A tool for a reliable market. Playing with currencies

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    The Forex market is a very interesting market. Finding a suitable tool to forecast currency behavior will be of great interest. It is almost impossible to find a 100 % reliable tool. This market is like any other one, unpredictable. However we developed a very interesting tool that makes use of WebCrawler, data mining and web services to offer and forecast an advice to any user or broker

    Equivalence of two approaches for the inhomogeneous density in the canonical ensemble

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    In this article we show that the inhomogeneous density obtained from a density-functional theory of classical fluids in the canonical ensemble (CE), recently presented by White et al [Phys. Rev. Lett. 84 (2000) 1220], is equivalent to first order to the result of the series expansion of the CE inhomogeneous density introduced by Gonzalez et al [Phys. Rev. Lett. 79 (1997) 2466].Comment: 6 pages, RevTe

    Tilted subwavelength gratings: controlling anisotropy in metamaterial nanophotonic waveguides

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    Subwavelength grating (SWG) structures are an essential tool in silicon photonics, enabling the synthesis of metamaterials with a controllable refractive index. Here we propose, for the first time to the best of our knowledge, tilting the grating elements to gain control over the anisotropy of the metamaterial. Rigorous finite difference time domain simulations demonstrate that a 45° tilt results in an effective index variation on the fundamental TE mode of 0.23 refractive index units, whereas the change in the TM mode is 20 times smaller. Our simulation predictions are corroborated by experimental results. We furthermore propose an accurate theoretical model for designing tilted SWG structures based on rotated uniaxial crystals that is functional over a wide wavelength range and for both the fundamental and higher order modes. The proposed control over anisotropy opens promising venues in polarization management devices and transformation optics in silicon photonics.Universidad de Málaga (UMA); Ministerio de Economía y Competitividad (MINECO) (IJCI-2016-30484, TEC2015-71127-C2-R, TEC2016-80718-R); Ministerio de Educación, Cultura y Deporte (MECD) (FPU16/06762); European Regional Development Fund (ERDF); Comunidad de Madrid (SINFOTON-CM S2013/MIT-2790); European Association of National Metrology Institutes (EURAMET) (H2020-MSCA-RISE-2015:SENSIBLE, JRP-i22 14IND13 Photind)

    Bimodal effect of water on V2O5/TiO2 catalysts with different vanadium species in the simultaneous NO reduction and 1,2-dichlorobenzene oxidation

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    VOX/TiO2 catalysts with different vanadium loading were prepared in order to study the influence of vanadium species on the effect of water in the simultaneous NO reduction through NH3-SCR and o-DCB oxidation reactions. The presence of isolated, polymeric and crystalline species and their redox and acid properties were evaluated by N2-Adsorption, XRD, Raman, H2-TPR, XPS and NH3-TPD. Water has a bimodal and reversible effect in both NO reduction and o-DCB oxidation depending on vanadium species and temperature. In SCR, water has a detrimental effect at low temperature due to competitive adsorption with NO and NH3, while at high temperature it promotes an increase of NO conversion associated to the suppression of side-reactions, which increase the selectivity towards N2. In o-DCB oxidation, the effect of water is the sum of two contributions: one positive, related to the removal of surface adsorbed detrimental species; and one negative, associated to the competitive adsorption with o-DCB. Thus, at high temperature water acts as inhibitor, while at low temperature water has a promotional effect in the highly dispersed vanadium catalysts due to their tendency to suffer deactivation, mainly by carbonaceous materials. The presence of water also favors total oxidation and decreases the formation of chlorinated by products.MINECO/FEDER (CTQ2015-64616-P), MINECO/FEDER (BES-2016-077849), IT657-13, IT1297- 19, INF12/37, UFI 11/39, PID2019-107503RB-I00, MCIN/AEI/10.13039/50110001103
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